Cross-reactivity between Parietaria pollen and beet.

Allergy to beet is very rare. Until now, only a few reports about asthma induced by inhaling the vapor of cooked beet have been published. We describe two patients with allergic rhinitis and positive skin prick tests to Parietaria and beet only. To investigate possible cross-reactivity between Parietaria pollen and beet, we performed laboratory assays that showed beet-specific IgE in the sera of both patients and possible cross-reactivity between Parietaria and beet in one patient.